Abstract: An electrohydraulic servovalve which includes as an integral part thereof a monitor valve which senses the absence or lack of system pressure in the first or second stages of the valve and translates in the absence thereof to deactivate load control. The torque motor of the electrohydraulic servovalve is biased, electrically or magnetically, to provide a failure indication in the first stage of the valve in the absence of or excess of applied electrical signals to the torque motor.

Abstract: An improvement in a servovalve employing spool-valve-position feedback provided by a feedback spring, wherein the feedback spring centerline is not aligned vertically with the center line of the spool valve, comprising a receiving hole in the spool valve body and a slot in the spool for feedback spring clearance; a pin or ball rigidly attached to the feedback spring with the portions of the pin or the ball which contact the sides of the receiving hole fitting in face to face relation to the inner surface of recesses formed in the slot by the hole.